.TH vsel 1 "Version VERSION"
.ds -- \-\^\-
.ds b[ \fR[\|\fP
.ds b] \fR\|]\fP
.SH NAME
vsel \- select parameters from a vamps output file
.SH SYNOPSIS
.B vsel
.B \*(b[\*(--help\*(b]
.B \*(b[\*(--Header\*(b]
.B \*(b[\*(--copyright\*(b]
.B \*(b[\*(--license\*(b]
.B \*(b[\*(--verbose\*(b]
.B \*(b[\*(--memuse\*(b]
.BI \*(b[\*(--Comment\  commentchar\*(b]
.BI \*(b[\*(--number\  layer\*(b]
.BI \*(b[\*(--time\  time\*(b]
.BI \*(b[\*(b[\*(--parameter\  parameter\*(b]...\*(b]
.BI \*(b[\*(--sKip\  skipfactor\*(b]
.BI \*(b[\*(--outfile\  outfile\*(b]
.BI \*(b[\*(--index\  indexfile\*(b]
.BI \*(b[\*(--Index\  indexfile\*(b]
.I filename

.SH DESCRIPTION
.B vsel
is a program for post-processing 
.B vamps 
output files (see  
.BR vamps (5)
). 
.B vsel
allows you select to a parameter from a 
.B vamps
output-file, either as a single value
at a specified time, or as a time-series.
Output is in white space delimited ASCII.
.B vsel
can use an index file to speed up random access to large files.

If you need a more low-level kind of access to
.B vamps
output files you can use
.BR getstr (1)
or
.BR issec (1).
You can also use the deffile.c library in your own programs.
Input is read from either
.I filename
or standard input. If
.I filename
is specified as a single dash
.RB `` \- '',
it is taken from standard input. 
If
.I outfile
is specified as a single dash
.RB `` \- '',
all output is send to standard output. 

.SH OPTIONS
Options may be given as either standard
one-letter options, or GNU style long options. Long options start with
two dashes
.RB `` \*(-- ''
and may be truncated to any unambiguous abbreviation.

.TP
.B \*(--copyright
Show copyright information and exit

.TP
.B \*(--license
Print license information and exit.

.TP
.B \*(--Header
Omit headers from output.

.TP
.B \*(--help
Print help text and exit.

.TP
.B \*(--verbose
Enter verbose mode, program progress is displayed on stderr.
Default is silent.

.TP
.BI \*(--Comment\  commentchar
Set the commentchar to char
.I commentchar.

.TP 
.B \*(--memuse
Use more memory. Use this option to speedup processing. Note that
a 4.9 Mb input file will cause
.B vsel
to grow to about 28 Mb while running if you use this option.
It is especially faster if you process multiple parameters in one run.
You should not use this option if the input-file is larger than 5 times
the amount of free physical ram.

.TP
.BI \*(--parameter\  parameter
Use parameter
.I parameter.
Multiple 
.B \-p
options are allowed to dump multiple parameters.

.TP
.BI \*(--index\  index
Use the index file
.I index

.TP
.BI \*(--Index\  index
Build an index in the file
.I index

.TP
.BI \*(--time\  time
Output only at time 
.I time.
Multiple 
.B \-t
options are allowed to dump multiple times. You
can also specify a range using the 
.B \-s
and 
.B \-e
options. If
no 
.B \-t
option or range is specified all times are included
in the output.

.TP
.BI \*(--sKip\  skipfactor
Skip every
.I skipfactor
times.

.TP
.BI \*(--number\  layer
Dump only layer
.I layer.
If no 
.B \-n
option is present all layers are dumped.
Numbering starts at 0.

.TP
.BI \*(--outfile\  outfile
Send all output to 
.I outfile
in stead of the stdout. If you specify \-, all output is send
to stdout.

.SH USAGE
.B vamps
output files contain strings, single floating point values and arrays of
floating point values. 
.B vsel 
can be used to extract a single parameter at a specified time or
a range of times. 

.SH EXAMPLES
Select the parameter theta (an array) at time 12 and time 23 in file out.tst:
.br
.B vsel \-t 12 \-t 23 \-p theta out.tst

To select cumprec (a single floating point value) for all times:
.br
.B vsel \-p cumprec out.tst


    
.SH SEE ALSO
.BR vamps (5),
.BR issec (1),
.BR getstr (1).


.SH AUTHOR
J. Schellekens
.br
schj@geo.vu.nl

.SH BUGS
If you use the
.B \-m
option vsel uses
.I lots!!
of memory. 
You should not use this option if the input-file is about 90% of
the computers free physical ram.
